* {
  padding: 0;
  margin: 0;
}
.container {
  border: 1px solid red;
  width: 1000px;
  height: 500px;
  display: flex;
}
.left {
  display: flex;
  align-items: center;
  justify-content: flex-start;
  flex-direction: column;
}
.left-img {
  width: 500px;
  height: 280px;
  background-image: url("./images/1.jpg");
  background-size: 100%;
  position: relative;
}
.mask {
  position: absolute;
  width: 50px;
  height: 50px;
  background-color: rgba(2, 131, 244, 0.534);
  border: 1px solid rgba(2, 131, 244, 1);
  opacity: 0;
}
.left-img-ul {
  list-style: none;
  display: flex;
}
li {
  width: 100px;
  height: 50px;
  background-size: 100%;
  background-repeat: no-repeat;
  margin: 10px;
  cursor: pointer;
}
.right {
  width: 500px;
  background-image: url("./images/1.jpg");
  background-size: 500%;
  background-repeat: no-repeat;
  opacity: 0;
}
